Thermostatic switch



June 10, 1924.

A. O. APPELBERG THERMOSTATIC SWITCH File d Jan.

.50 vided with a nut 10. Inte thehaidbfthescrewt) and e contact arm Patented June 10, 1924.

EU-NITEDASTATES PATENT OFFICE.

Alma OSVALD APPELIBEBG, OF STOCKHOLI, SWEDM, ASSIGNOR '10 AKT'IEBOLAGE'I BIB-KL REGULATOR, OI STOCKHOLI, SWEDEN.

THERIOSTA'IIG SWITCH.

Application filed January 20, 1923. Serial No. 618,920.

To all whom it may concern.

Be it known that AXEL OSVALD Arrnmsnnc, a subject of the King of Sweden, residing at 11 Roslagsg'atan, Stockholm, Sweden, has invented certain new and useful Improvements in Thermostatic Switches, of which the following is a specification.

The invention relates to thermostatic switches of the kind which are disposed in hermetically closed glass receptacles for the purpose of protecting the break contact of the switch, and the main object of the invention is to facilitate the manufacturing of such thermostatic switches. I The invention consists in the construction and novel combination and the arrangement of parts as well as the method of' manufacturing-hereinafter fully described, illustrated in the accompanying drawing and set forth in the claims hereunto appended.

In the drawings: F" 1, 2 and 3 are three different views of the t ermostatic switch the glass receptacle I being shown in section.

Fig. 4 shows the base ofthe receptacle with the connecting terminals, mounted thereon.

Fig. 5 shows the insulating stud whereby so the switch is secured to the connectingterminals. b Fig. 6 shows the switch detached from the ase.

The switch consists of two contactarms a5 1, 2 and a thermostatic element 3 fastened to the contact arm 1 by a rivet 4. The contact arm last mentioned consists of a thin plate. spring carrying at its outer end a contact 'plate 5. Rivetedto said plate 5 is one of the two contact pins 6, 7 forming the break contact ofthe switch. Said contact pins preferably consist of tungsten or other refractory metal. The contact arm 2 carrying" the-other contact pin 7 consists of a 'stri of metaliwhich is relatively stifi.

connected-with one another by means of an insulating stud .8 and a screw 9 passed through a central hole of the stud and prosed between e two contact arms land 2 are firmly the connection last mentioned the contact arms are also secured to two corresponding terminal plates 18, 19 and thereby rigidly connected with the base or bottom 20 of the tubular glass receptacle 21, the terminals 18,

19 being sealed in the base 20 and electrically connected with the outer conductors 22, 23.v

Instead of the screws 9, 1 1 rivets may, evidently, be used to keep the parts together.

The thermostatic element 3 consists of a bimetallic strip secured in lace by the connecting device 8, 9. It is a apted to be bent, upon an increase of temperature, towards the contact arm 1 and to operate said contact arm so as to open the contact 6, 7 at a certain temperature. The receptacle 21 may be either evacuated or filled with an inert The object'of constructing the switch in the way described is to facilitate the manufacturing and. adjustment of theswitch.

Heretofore, in the manufacture of suchswitches the contact arms have usually been sealed directl into the glass base, the switch being then a justed and fastened in the receptacle by sealing the base onto one end of the rece ta'cle. This method, however, has the disa vanta that the contact arms may easily be broug t out of their adjusted position, when the switch is being inserted in the receptacle. Such disadvantage is now removed according to the present invention by the switch being made up of two different parts, one of which consists of, the switch member shown in Fig. 6, while the other art consists of the glass base 20, shown in Fig. 4, together with the contact terminals 18, 19 mounted-thereon. The said two parts may, consequently,-be manufactured separately independent of one another; As will appear from Fig. 6, the contact arms -1, 2 and the thermostaticelement3 ma thus be rigidly connected with one-another y means of the'connect' device 8, 9--s0 as to make it possible to ad ust the switch properly before it is secured to the glass base. Such an adjustment may for instance be efiected by bending the spring 1 and by setting a screw 24 provided at the outer end of the bimetallic strip" 3, said screw being accessible through an aperture 25. in the contact arm 2. After the. switch member and the glass base 20 with its contact terminals having been thus manufactured separately the two parts. are

connected together as shown in Fig. 2 by means ofthe insulating stud 13 and the screw 14, the fork-shaped ends of the contact terminals 18, '19 being clamped between the'insulating stud and the contact arms. Il1' thlS way the terminals are connected at the same time electrically with the contactarms. The switch is thenintroduced into the tube 21, wherein it is fixed in place by sealing the glass base 20 onto one end of the tube. Finally, the tube is evacuated or filled with gas and closed up similar y as ordinary: electrical incandescent lamps.

The thermostatic switch shown in the drawin is adapted to be placed directly in therma connection with the source of heat to be controlled, but, evidently the switch .may'be operated indirectly by means of heating resistance placed around or inside the receptacle or on the thermostatic element.

I claim: v.

' 1; In a thermostatic switch disposed in a closed receptacle the combination of a contact device, a number of connecting terminals attached to the base of the'receptacle and means for connecting said contact device and said. terminals mechanically and electrically. v Y

2 In a thermostatic switch disposed in a closed receptacle the combination of a number ofcontact members, means for connect-'- ing said contactmembers mechanically, a

number ofconnecting. terminals attached to the base of the receptacle and. means for connecting 'said'c'ontact" members and said terminals mechanically and electricall 3.-In a thermostatic switch dispose in a" closed glass receptacle the combination of two contactarms, means for connecting said tricallycomprisin'g aninsulating. connecting piece and a together. v p 5. In a thermostatic switch disposed in a a closed glass receptacle the combination. of two contact arms, means for connecting said contact arms mechanically comprising an insulating stud, insulating washers and a pin passed. through said stud and arranged to clam the parts together, two connecting pin adaptedtohold the parts terminas sealed in the base of the .rece p tacle and means for connecting said contact arms and terminals mechanically and elecsulating washers and apin passed through said stud and arranged to clampthe parts together.

6. 'In. a closed glass receptacle the combination of two contact arms, athermostatic stem, means for connecting said contact arms and thef'mostatic stem mechanically, two connecting terminals sealed in the base -of the trically comprising an insulatingstud, in-- thermostatic switch disposed in a v receptacle and. means for connecting said contact arms and terminals mechanically nd electrically. 7. A-- methodof manufacturing thermo static switches consisting in making sepafl rately a switch support with connectin termlnals attached theretoand a switc composed of a number of contact members mechanically connected together, copnectin said switch and support y means of sai terminals, inserting the switch .in a receptacle, fastening the support to the receptacle, evacuating the receptacle and closing the receptacle hermetically.

8. A method of manufacturing thermostatic switches consisting in making sepa 'minals attached thereto and a switch composed .of. a. number of contact members mechanically connected together, connecting said switch and support by means-offsaid terminals, inserting the switch in a-receptacle, fastening the support to the receptacle, filling the receptacle with inert gas and closing the receptacle hermetically.

static switches consisting in makin separately a switch support of glass with .ter-

rately a switch support with connecting termethod of manufacturing thermominalplates sealed therein and a switch composed of two contact arms clamped together by means of an insulating stud and a connecting pin passed through the stud,-

connecting said switch and. support by clamping said contact arms-and terminals together, inserting the switch in a glass receptacle, sealing the support onto one end of the receptacle, evacuating the receptacle and .closing the receptacle hermetically at the other end. v

10. A method of manufacturing thermostatic switches consisting in makin separately a switch sup ort of glass with terminal plates sealed t rein and 'a switch composed of two contact arms clamped together by means of an insulating stud and a Connecting pin passed through the stud, connecting said switch and support by clamping said contact arms and terminals together, inserting the switch in a glass receptacle, sealing the support onto one end of the receptacle, filling the receptacle with .inert gas and closing the receptacle her- A XEL OSVALD APPELBERG. Witnesses OSCAR GRAHN,

L. BERGE LINDE. 

